Benign prostatic hyperplasia: does prostate size matter?

Recent studies and analyses have confirmed that baseline prostate volume is related to progression of benign prostatic hyperplasia (BPH) as well as to negative outcomes related to BPH, such as acute urinary retention (AUR) and need for surgery, and can also predict response to therapy. Other investigations have determined that prostate-specific antigen (PSA) level has good predictive value for assessing prostate volume. Strong evidence exists that baseline serum PSA level, like baseline prostate volume, predicts future prostate growth. Randomized placebo-controlled finasteride trials have shown that men with larger prostate volumes and higher PSA levels experience a clinically significant response to therapy compared with those with smaller prostate volumes and lower PSA levels. It has also been demonstrated that men with larger prostate glands and higher PSA levels are at increased risk for AUR and BPH-related surgery but that finasteride reduces these risks. Moreover, doxazosin and finasteride, alone and in combination, have been shown to significantly reduce BPH clinical progression.     

5-alpha-Reductase Inhibitors Prevent the Progression of Benign Prostatic Hyperplasia

Lower urinary tract symptoms (LUTS) associated with clinical benign prostatic hyperplasia (BPH) are a common occurrence in aging men, causing bother and interference with daily activities and affecting disease-specific quality of life. There is increasing evidence to suggest that, in many patients, the signs and symptoms of BPH are progressive. Progression can be measured as continued growth of the prostate gland; worsening of symptoms, bother, or quality of life; deterioration of urinary flow rate; episodes of acute urinary retention (AUR); and need for prostate-related surgery. Furthermore, it has become clear that the risk of disease progression increases with age as well as with increasing prostate volume and serum prostate-specific antigen (PSA) level. The 5-alpha-reductase inhibitor finasteride has been shown not only to improve symptoms, bother, and quality of life but also to prevent progression to AUR and surgery, with a relative risk reduction of over 50%. As the risk for such progression is higher in patients with larger glands or higher serum PSA values at baseline, it is in those patients that finasteride induces an even greater risk reduction, making it a cost-effective treatment choice for patients with LUTS associated with prostatic enlargement.     

Landmark studies impacting the medical management of benign prostatic hyperplasia

The treatment of benign prostatic hyperplasia (BPH) has changed dramatically over the past 10 years. Phase 3 studies of the safety and effectiveness of alpha-blockers (eg, terazosin and doxazosin) and 5-alpha-reductase inhibitors (eg, finasteride) for the treatment of BPH began to appear in the literature in 1992. This article reviews the results of landmark studies of these agents, either separately as monotherapy or as combined therapy, for the treatment of BPH. The relationship between prostate size and lower urinary tract symptoms (LUTS) is discussed. Although prostate volume is not as strongly correlated with these symptoms as was once believed, it has been shown to be an important predictor of risk for developing acute urinary retention. alpha-Blockers represent an effective treatment for LUTS independent of prostate volume; the clinical benefit of finasteride for LUTS is limited primarily to men with large prostates. Finasteride decreases the risk of progression to acute urinary retention and the requirement for surgical intervention; this benefit is greatest in men with enlarged prostates.     

The clinical development of a 5 alpha-reductase inhibitor, finasteride.

Finasteride, a 4-aza steroid compound, is an orally active inhibitor of the 5 alpha-reductase enzyme. 5 alpha-Reductase is necessary for the metabolism of testosterone (T) to dihydrotestosterone (DHT) and is found in high levels only in certain tissues such as the prostate. Finasteride has been shown to markedly suppress serum DHT levels in man without lowering testosterone levels. In patients with benign prostate hyperplasia (BPH), finasteride was found to decrease prostate volume by a mean of 28% over a period of 6 months, without causing clinically significant adverse effects. DHT appears to be the primary androgen for prostatic growth. Selective inhibition of 5 alpha-reductase by finasteride may provide a novel approach to BPH therapy by reducing prostate size without affecting T-dependent processes such as fertility, muscle strength, and libido. The clinical development of finasteride for the treatment of benign prostate hyperplasia is reviewed.     

Medical treatment of benign prostatic hyperplasia

Medical therapy for the treatment of benign prostatic hyperplasia (BPH) became an accepted standard of care in the 1990s following the reports of randomized, double-blind, placebo-controlled studies showing that finasteride, a 5-α reductase inhibitor, and terazosin, an α-blocker, significantly improved lower urinary tract symptoms and increased peak urinary flow rates in men with BPH. This article reviews novel approaches to the pharmacological treatment of BPH.     

Adénome prostatique, hormones et androgénothérapie

The prostate is an androgen dependent organ. Benign prostatic hyperplasia (BPH) has a high prevalence in histological studies, but all the affected men do not present symptoms. Aging and the presence of androgens are the main determinants of BPH. However, androgen blood levels were not higher in patients with BPH than in the general population. Suppression of androgens induced a decrease in prostatic volume. Androgen replacement therapy resulted in a re-increase of prostatic volume, but during androgen replacement therapy the prostate volume was only slighty increased, it any, thus remaining within normal range. The present review of the literature indicates that BPH is no a contra-indication for androgen replacement therapy in men with partial or complete androgen deficiency. However, it must be noticed that in most of the studies published so far subjects with BPH have been excluded. A specific study involving such patients is to be undertaken.     

Serum prostate-specific antigen determination in prostatic carcinoma

Prostate-specific antigen (PSA) is a tissue-specific glycoprotein identified by Wang in 1979. It is synthesized in the prostate independently of prostatic acid phosphatase (PAP). A total of 199 subjects were divided into four groups: controls aged less than 50 years, controls aged more than 50 years, patients with benign prostatic hyperplasia (BPH) and patients with prostatic carcinoma. PSA cut-off value was set at 10 ng/ml (mean for the BPH group plus 2 SD). With this cut-off value PSA could not be used as an early predictor of prostatic carcinoma. The association of PSA and PAP in prostatic cancer increases the number of patients with positive biological markers.     

Economic impact of surgical intervention in the treatment of benign prostatic hyperplasia

The economic burden of benign prostatic hyperplasia (BPH) on our health care system is significant and likely to continue to grow given the burgeoning elderly population. Coincident with the rising number of annual physician office visits and expenditures for BPH has been a dramatic shift in the disease's management, from surgical to medical care. However, long-term cost data call into question the appropriateness of medical therapy as the initial treatment approach for all men with BPH, particularly those with moderate to severe symptoms. Although there has been a paradigm shift away from traditional BPH surgery, there has been renewed interest in the treatment of BPH with novel surgical techniques and minimally invasive surgeries. The economics of surgical interventions for BPH are discussed.     

Lower urinary tract symptoms, benign prostatic hyperplasia, erectile dysfunction, and phosphodiesterase-5 inhibitors

Many patients who present to their healthcare provider with lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) will also have erectile dysfunction (ED), and vice versa. Although alpha-adrenergic receptor blockers and 5-alpha-reductase inhibitors are highly effective in treating BPH-associated LUTS, these agents have sexual adverse effects that cause many men to discontinue therapy. The discovery of nitric oxide as a major factor in the mechanism of erection has led to the development of new drugs for ED, including the phosphodiesterase (PDE) inhibitors. Preliminary data support the theory that inhibition of PDE isoenzymes in the prostate may improve LUTS due to BPH through relaxation of prostatic smooth muscle. Further studies of PDE inhibitors in men with ED and BPH-associated LUTS are indicated.     

Quality of life and sexual function in patients with benign prostatic hyperplasia

Incidence of benign prostatic hyperplasia (BPH), one of the most common conditions affecting adult men, increases dramatically after the age of 50. The various symptoms of BPH, which include lower urinary tract symptoms (LUTS), can adversely affect quality of life (QOL). Many men with BPH and LUTS wait until symptoms become significantly bothersome before seeking medical attention. Evaluating the exact severity and significance of symptoms has been difficult with previous methodology. Over the last decade, assessment tools have become available to quantify the symptoms of BPH and LUTS. This article addresses the impact of BPH, its management, and the overall effects it has on QOL.     

Malondialdehyde in benign prostate hypertrophy: a useful marker?

Benign prostate hypertrophy (BPH) is the most common benign tumor in men due to obstruction of the urethra and, finally, uremia. Malondialdehyde (MDA) is a product derived from peroxidation of polyunsaturated fatty acids and related esters. Evaluation of MDA in serum represents a non-invasive biomarker of oxidative stress. Prostate-specific antigen (PSA) is a sensitive marker for prostatic hypertrophy and cancer. We analyzed MDA serum levels to evaluate the oxidative stress in BPH. To this end, 22 BPH patients and 22 healthy donors were enrolled. Data show an increase of MDA level in BPH patients and a positive correlation between PSA and MDA levels. In conclusion, we describe a previously unknown relationship between PSA and MDA as an index of inflammation and oxidative stress in BPH.     

Comparison of Saw Palmetto (extract and whole berry) and Cernitin on prostate growth in rats

Pharmaceuticals such as finasteride and alpha blockers are used to treat symptoms of benign prostatic hyperplasia (BPH) and are known to cause severe adverse reactions. Accordingly, a search for safer, natural products has been undertaken. Two natural agents (nutraceuticals) have come under recent scrutiny; because natural products, in general, often have evidence of long-term safety. The present study compares the in vivo effects on androgen-induced prostatic enlargement in rats of two nutraceuticals – the widely recognized Saw Palmetto (Serenoa repens) and the less well-known Cernitin (defined pollen extract). Non-castrated rats, had a mean prostate weight of 124 mg ± 8.8 (S.E.M.) compared to the 24.5 mg ± 1.9 (S.E.M.) of the castrated rat followed under the same regimen (p < 0.01). When castrated rats were given testosterone, the mass increased significantly to 250.0 mg ± 31.7 (S.E.M.) (p < 0.01). In the five remaining groups, castrated rats receiving testosterone were given finasteride, an extract of Saw Palmetto, crushed whole berry derived from Saw Palmetto fruit, a water soluble and fat soluble extract of Cernitin or a combination of the Saw Palmetto extract and Cernitin. All treatments decreased the size of the prostate to roughly the same size as in the non-castrated rats, a size that was significantly smaller than castrated rats treated with testosterone in the same manner (p < 0.01). A second study examining non-castrated rats treated with very high doses of testosterone showed similar results. In both studies, the nutraceuticals generally decreased body weight. In conclusion, these studies show the ability of Saw Palmetto (whole berry and extract) and Cernitin to influence prostatic hyperplasia via effects on androgen metabolism.     

Protocatechuic acid ameliorates testosterone‐induced benign prostatic hyperplasia through the regulation of inflammation and oxidative stress in castrated rats

Protocatechuic acid (PA) is a polyphenol—recognized for its efficacy as an antioxidant—possesses anticancer, anti‐inflammatory, antioxidant properties. The efficacy of PA in the management of benign prostatic hyperplasia (BPH) has not been investigated. Forty‐two castrated rats (n = 7) were treated as follows: control (corn oil), BPH only received testosterone propionate (TP) (TP 3 mg/kg intraperitoneally), BPH + PA (TP 3 mg/kg + PA 40 mg/kg), BPH + finasteride (Fin) (TP 3 mg/kg + Fin 10 mg/kg), PA only (40 mg/kg: by gavage), and Fin only (10 mg/kg: by gavage) for 4 weeks. In BPH rats, there were significant (P < .05) increases in prostatic (250%) and organosomatic (280%) weights compared with controls. Cotreatment decreased prostatic weights by 19% (PA) and 21% (Fin). Markers of inflammation: myeloperoxidase activities increased in serum (148%) and prostate (70%), as well as nitric oxide levels serum (92%) and prostatic (95%). Proinflammatory cytokines interleukin‐1β and tumor necrosis factor‐α increased by 3.6‐ and 2.8‐fold. Furthermore, prostatic malondialdehyde, superoxide dismutase, and serum total acid phosphatase increased by 97%, 25%, and 48%, respectively. Histology revealed poor architecture and severe proliferation of the prostate in BPH rats. Inflammation and oxidative stress markers, as well as the histological alteration in BPH rats, was attenuated (P < .05) upon cotreatment with PA and comparable with Fin cotreatment. These results suggest that PA mitigates oxido‐inflammatory responses and restored prostatic cytoarchitecture to levels comparable with control in rats induced with BPH.     

Evaluation of specific antigen and prostatic acid phosphatase specificity. Study of false values

We assayed prostatic specific antigen (PSA) and prostatic acid phosphatase (PAP) serum levels in 1305 subjects without malignant prostatic pathology by double antibody RIA I125 to evaluate their specificity. When we set a second upper normal limit of 10 ng/ml for PSA and 2.5 ng/ml for PAP there was a significant increase of specificity. There were 2 and 3.7% false positive results in non-prostatic benign pathologies, 1.8 and 7.9% in non-prostatic malignant, 3.5 and 4.7% in non-complicated benign prostatic hypertrophy (BPH) and 3.3% for both in chronic prostatitis. In patients with complicated BPH and acute prostatitis the results were 64.8 and 24% for PSA and 20 and 16% for PAP. In conclusion, PSA is more specific than PAP in patients without acute inflammatory pathology of the prostate; the high rate of false positive values in the latter excludes its usefulness in these patients as diagnostic tumoral markers.     

Alpha blockers for the treatment of benign prostatic hyperplasia

The evolution of alpha blocker therapy for benign prostatic hyperplasia (BPH) has focused on improving convenience and tolerability. Indications for treating BPH include reversing signs and symptoms or preventing progression of the disease. The indication that most commonly drives the need for intervention is relief of lower urinary tract symptoms (LUTS) with the intent of improving quality of life. Alpha blockers are the most effective, least costly, and best tolerated of the drugs for relieving LUTS. Four long-acting alpha 1 blockers are approved by the Food and Drug Administration for treatment of symptomatic LUTS/BPH: terazosin, doxazosin, tamsulosin, and alfuzosin. All are well tolerated and have comparable dose-dependent effectiveness. Tamsulosin and alfuzosin SR do not require dose titration. Alfuzosin, terazosin, and doxazosin have all been shown to be effective in relieving LUTS/BPH independent of prostate size.     

Contribution of Genetic Variation rs266882 to Prostate-Specific Antigen Levels in Healthy Controls with Serum PSA Below 2.0 ng/ml

We evaluated the impact of genetic variation in the prostate-specific antigen (PSA) gene (rs266882) on serum PSA levels in healthy men as well as risk factors for benign prostate hypertrophy (BPH) and prostate cancer. The study population comprised 91 men with PSA levels below 2.0 ng/ml as healthy controls, 78 men with PSA 2–10 ng/ml as a BPH group, and 128 prostate cancer patients, all in Korea. DNA was amplified by polymerase chain reaction and the product was sequenced. We found that PSA levels were associated with a G/A polymorphism only in healthy controls. The transition, however, was not associated with PSA levels of BPH and cancer patients, nor was it a risk factor. In conclusion, this genetic factor is important for determining serum PSA levels in the naive group, whereas the disruption of prostatic architecture in BPH or prostate cancer may be a major determining factor for PSA levels.     

Down-regulation of prostate specific antigen in LNCaP cells by flavonoids from the pollen of Brassica napus L.

The pollen of Brassica napus L. has been used in China to treat benign prostatic hyperplasia (BPH) for over decades. In this study, the pollen of Brassica napus L. was extracted successively with chloroform, ethyl acetate and ethanol. The ethyl acetate extract showed strong activity in decreasing the secretion of prostate specific antigen (PSA) in LNCaP cells as compared to two other extracts, measured by ELISA with finasteride as positive control in the assay. Five flavonoids were subsequently isolated from the active extract using bioassay-guided fractionation. They were Naringenin (1); Luteolin (2); Kaempferol (3); Kaempferol 3-(3-E-p-coumaroyl-alpha-L-rhamnopyranoside) (4); and Kaempferol 3-(2,3-di-E-p-coumaroyl-alpha-L-rhamnopyranoside) (5). All these compounds inhibited PSA secretion significantly, with IC50 values in the range of 5-50 microM. Compounds 2, 4 and 5 showed moderate cytotoxicity to LNCaP cells within the active concentration range, while compounds 1 and 3 showed no cytotoxicity. Further studies on the mechanism action of these compounds were performed by evaluating their activation of estrogen receptor (ER) and antagonistic activities on androgen receptor (AR) in cell-based reporter gene assays. All compounds described here were first isolated from the pollen of Brassica napus L.     

A multiscale, mechanism-driven, dynamic model for the effects of 5α-reductase inhibition on prostate maintenance

A systems-level mathematical model is presented that describes the effects of inhibiting the enzyme 5α-reductase (5aR) on the ventral prostate of the adult male rat under chronic administration of the 5aR inhibitor, finasteride. 5aR is essential for androgen regulation in males, both in normal conditions and disease states. The hormone kinetics and downstream effects on reproductive organs associated with perturbing androgen regulation are complex and not necessarily intuitive. Inhibition of 5aR decreases the metabolism of testosterone (T) to the potent androgen 5α-dihydrotestosterone (DHT). This results in decreased cell proliferation, fluid production and 5aR expression as well as increased apoptosis in the ventral prostate. These regulatory changes collectively result in decreased prostate size and function, which can be beneficial to men suffering from benign prostatic hyperplasia (BPH) and could play a role in prostate cancer. There are two distinct isoforms of 5aR in male humans and rats, and thus developing a 5aR inhibitor is a challenging pursuit. Several inhibitors are on the market for treatment of BPH, including finasteride and dutasteride. In this effort, comparisons of simulated vs. experimental T and DHT levels and prostate size are depicted, demonstrating the model accurately described an approximate 77% decrease in prostate size and nearly complete depletion of prostatic DHT following 21 days of daily finasteride dosing in rats. This implies T alone is not capable of maintaining a normal prostate size. Further model analysis suggests the possibility of alternative dosing strategies resulting in similar or greater effects on prostate size, due to complex kinetics between T, DHT and gene occupancy. With appropriate scaling and parameterization for humans, this model provides a multiscale modeling platform for drug discovery teams to test and generate hypotheses about drugging strategies for indications like BPH and prostate cancer, such as compound binding properties, dosing regimens, and target validation.     

血清PSA、EGF在不同类型良性前列腺增生患者中表达意义及其与术后疾病转归的相关性分析

摘要 目的：分析血清前列腺特异抗原（PSA)、表皮生长因子（EGF)在不同类型良性前列腺增生患者中低表达意义及其与术后疾病转归的相关性。方法：选择自2020年1月至2022年12月在我院接受手术治疗的128例良性前列腺增生患者作为研究对象,根据术后病理活检结果进行分组,间质结节组（16例）、腺肌性结节组（32例）、纤维腺瘤性结节组（12例）、腺性结节组（30例）和混合结节组（38例）,其中以间质增生为主60例、以腺体增生为主68例。检测所有患者血清PSA、EGF的表达水平,以术后6个月的国际前列腺症状评分（IPSS评分）<8分判定为预后良好,分析血清PSA、EGF在预后良好组与预后不良组之间的差异性及与IPSS评分的关系。结果：血清PSA、EGF表达水平在间质结节组、腺肌性结节组、纤维腺瘤性结节组、腺性结节组和混合结节组间比较有差异（P<0.05）;以腺体增生为主的良性前列腺增生患者血清PSA、EGF表达水平均明显高于以间质增生为主的患者（P<0.05）;经ROC曲线分析,血清PSA联合EGF预测以腺体增生为主的良性前列腺增生的敏感度为86.42%,特异度为65.34%,AUC为0.930;所有患者均获得随访6个月,预后良好98例、预后不良30例;预后不良组血清PSA、EGF表达水平均明显高于预后良好组（P<0.05）;经Pearson相关性分析,良性前列腺增生患者血清PSA、EGF表达水平均与IPSS评分呈负相关（r值分别为-0.348、-0.417,P值均为0.000）。结论：血清PSA、EGF在不同病理类型良性前列腺增生患者中表达差异显著,以间质增生为主的患者,以腺体增生为主的患者血清PSA、EGF表达水平更高,两者均与术后疾病转归密切相关,值得临床予以重视。